Automatically reversible pumping mechanism



Sept. 20, 1966 D. TOTHERO 3,273,501

AUTOMATICALLY REVERSIBLE PUMPING MECHANISM Filed Oct. 1, 1964 5 Sheets-Sheet 1 INVENTOR. DWIGHT L. Tu THERE] A T TUENEY Sept. 20, 1966 D. L. TOTHERO AUTOMATICALLY REVERSIBLE PUMPING MECHANISM 3 Sheets-Sheet 2 Filed 001;.

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INVENTOR. DVYIGHT L. TDTHBRD ATTORNEY Sept. 20, 1966 D. 1.. TOTHERO 3,273,501

AUTOMATICALLY REVERSIBLE PUMPING MECHANISM Filed Oct. 1, 1964 5 Sheets-Sheet 3 Fl G. 5

INVEN'TOR. DWIGHT L. T UT HERE! ATTURNEY United States Patent M 3,273,501 AUTOMATICALLY REVERSIBLE PUMPWG MECHANISM Dwight L. Tothero, York, Pa, assignor to Carrier (Zorporation, fiyracuse, N.Y., a corporation of Delaware Filed Oct. 1, 1964, Ser. No. 400,692 7 Claims. (Cl. 103-3) This invention relates to pumps, and more particularly, to automatically reversible gear pumps.

Gear type pumps are widely employed as a means for circulating lubricant in machinery such as compressors and internal combustion engines. In certain applications, however, it is essential that the gear pump be automatically reversible, that is, that irrespective of whether or not the pump be driven in a clockwise or counterclockwise direction, the flow of fluid through the pump continues unabated in the same direction. For example, the use of a gear type pump as lubricant circulating means in motor driven compressors, compressors with lubrication systems engineered for unidirectional lubricant flow, necessitates that the pump be capable of reverse operation automatically inasmuch as power input to the compressor driving motor, which is determinative of the direction of compressor and hence pump rotation, may at some time be inadvertently reversed.

It is a principal object of the present invention to provide a new and improved automatically reversible gear type pump.

It is an additional object of the present invention to provide a gear type pumping mechanism, effective, on reversal in the direction of pump rotation, to re-orient the pump components to maintain unidirectional flow of the fluid being pumped.

It is an object of the present invention to provide an economical gear pump incorporating a simplified reversing mechanism.

This invention relates to an automatically reversible pumping mechanism comprising in combination an externally toothed inner pump gear rotatable about a first axis; an internally toothed outer pump gear; a carrier having a gear journalling opening therein dimensioned to rotatably receive the outer gear, the axis of the carrier opening being offset from the first axis, the carrier being adapted to circumscribe the inner gear to hold the outer gear in meshing engagement with the inner gear, the pump gears when rotated forming intake and exhaust spaces; rotatable driving means operatively secured to the inner gear; means forming suction and discharge passageways including a first port member on one side of the gears having an opening therethrough opposite the intake space and a second port member on the other side of the gears having an opening therethrough opposite the discharge space; and means accommodating predetermined rotation between the carrier and the first and second port members about the first axis upon a reversal in gear rotation to maintain the intake and exhaust spaces opposite the first and second port member openings.

Other objects will be apparent from the ensuing description and drawings in which:

FIGURE 1 is a sectional view of the pump assembly illustrating one embodiment of the invention;

FIGURE 2 is an exploded perspective view of the pump mechanism of FIGURE 1 illustrating the position of the pump parts on rotation in a counterclockwise direction;

FIGURE 3 is a sectional view taken along lines 3-3 of FIGURE 1 illustrating the position of the pump parts on rotation in a clockwise direction;

FIGURE 4 is a sectional view of the pump assembly illustrating a second embodiment of the invention;

3,273,501 Patented Sept. 20, 1966 FIGURE 5 is an exploded perspective view of the pump mechanism of FIGURE 4 illustrating the position of the pump parts on rotation in a counterclockwise direction; and

FIGURE 6 is a sectional view taken along lines 6-45 of FIGURE 4 illustrating the position of the pump parts on rotation in a clockwise direction.

Referring particularly to the drawings, there is shown an automatically reversible gear type pump mechanism embodying the invention for use as an oil pump in a compressor. It will be obvious that applicants pump mech anism may be used to pump other fluids and in different environments equally as well.

Referring to FIGURES 1-3, applicants improved pump mechanism 2 is operably positioned in cylindrical cavity 3 in compressor bearing head 4 between crankshaft 8 and retainer 9. Retainer 9 is fixedly secured to bearing head 4 by suitable means (not shown). Compressor crankshaft 8, rotatably supported by bearing 7, has pump drive extension 14 protruding therefrom. Cylindrical recess It] in crankshaft 8 communicates pump mechanism 2 with feed passages 11 in crankshaft 8. Lateral passage 12 in crankshaft 8 communicates feed passage 11 with hearing '7.

Pump mechanism 2 includes discharge port plate 20, rotatable gear journalling member 21, and suction port plate 22. Bearing head 4 is cut out or recessed at 6. Discharge and suction port plates 20, 22 have radially extending sides 24, 25, respectively, cooperable with recess 6, t0 fix plates 20, 22 against rotation. Recess 6 in bearing head 4 extends through an are slightly greater than Stop 26 on gear journalling member 21 cooperates With recess 6 to limit rotation of gear journalling member 21 to approximately 180.

Port plates 20, 22, have openings 33, 34 respectively therethrough for rotatably receiving pump drive extension 14 of crankshaft 8. Port 28 in discharge polt plate 20 communicates the discharge side of pump mechanism 2 with crankshaft recess 10. Port 29 in section port plate 22 communicates the suction side of pump. mechanism 2 through opening 35 in retainer 9 with a suitable source of fluid to be pumped such as the compressor sump.

Gear journalling member 21 has a generally cylindrical opening 30 therethrough with an axis parallel to and spaced from the axis of crankshaft 8. Internally toothed outer pump gear 32 having an outer dimension slightly less than the dimension of opening 30 in member 21 is rotatably positioned in opening 30. Externally toothed inner pump gear 16 having one less tooth than outer gear 32 is drivingly positioned on crankshaft extension 14 in mesh with outer gear 32. The eccentric relationship established by the parallel but nonconcentric axes of rotation of pump gears 16, 32 is such that full tooth engagement between gears 16, 32 occurs at a single point only.

Spring 36 between retainer 9 and suction port plate 22 resiliently maintains the pump components in operative relationship.

Referring to FIGURE 2, counterclockwise rotation of crankshaft 8 as shown by the arrow drives meshing pump gears 16, 32 in a counterclockwise direction. Stop 26 holds journalling member 21 against counterclockwise movement. Lubricant is drawn through suction port 29 in plate 22 between the teeth of gears 16, 32 and discharged through discharge port 28 in plate 20 into crankshaft recess 10 and feed passage 11 into the compressor lubrication system.

On a reversal in the direction of rotation of crankshaft 8 and correspondingly meshing pump gears 16, 32 from the counterclockwise direction shown in FIGURE 2 to a clockwise direction shown by the arrow in FIGURE 3, the frictional drag exerted by the lubricant between rotating pump gear 32 and journalling member 21 moves jour nalling member 21 clockwise through an arc of approximately 180, stop 26 holding member 21 against further clockwise rotation. The axis of rotation of outer pump gear 32 is displaced through an arc of approximately 180 so that the clockwise rotation of gears 16, 32 draws lubricant through opening 35 and suction port 29 between the teeth of gears 16, 32 and discharges lubricant through discharge port 28 into crankshaft recess 1.0 and feed pas sage ll.

While gear journalling member 21 is arranged for limited rotation about the axis of crankshaft 8 with discharge and suction port plates 20, 22 fixed against rotation, it is understood that both discharge and suction port plates 20, 22 may, in the alternative, be arranged for limited rotation about the axis of crankshaft 8 with gear journalling member 21 fixed against rotation. In that event, plates 20, 22 each include means, such as stop 26 of member 21, to limit rotation of plates 20, 22 to approximately 180. Gear journalling member 211 includes means such as side 24 of discharge port plate 20, to prevent rotation of member 2 1.

On counterclockwise rotation of crankshaft 8 plates 20, 22 and gear journalling member 21 are in the position illustrated in FIGURE 2 of the drawings, lubricant passing through suction port 29 between gears 16, 32 and discharging through port 28 into the compressor lubrication system.

On a reversal in rotation of crankshaft 8 from counterclockwise to clockwise direction the frictional drag between rotating gears 16, 32 and plates 20, 22 moves plates 20, 22 clockwise through an arc of approximately 180. The operation of the pump mechanism upon reversal of crankshaft rotation remains unaffected.

In the embodiment shown in FIGURES 4-6, pump mechanism 40 is operably positioned in cylindrical cavity 41 formed in compressor bearing head 42 between crankshaft 46 and retainer 44. Retainer 44 is fixedly secured to bearing head 42 by suitable means (not shown). Compressor crankshaft 43, rotatably supported by bearing 45, is drivingly connected through extension 46 to inner pump gear 47. Recess 48 in crankshaft 43 communicates pump mechanism 40 with lubricant feed passages 49', 50 in crankshaft 43.

Pump mechanism 40 includes paired discharge port plates 52, 53; gear journalling member 54; and paired suction port plates 56, 57. Recess 59 in bearing head 42 extends through an arc slightly greater than 90. Discharge and suction port plates 52, 56 each include a stop 61, 6 2, respectively, cooperable with recess 59 in bearing head 42 to limit rotation of plates 52, 56 to approximately 90. Discharge and suction port plates 53, 57 each have a radially extending side 63, 64, respectively, cooperable with recess 59 to prevent rotation thereof. Side 66 on gear journalling member 54 cooperates with recess 59 to prevent rotation of member 54.

Plates 52, 53 and 56, 57, respectively, have openings 68, 6'8 and 70, 70 therethrough for receiving pump drive extension 45. Plates 52, 56 have substantially semicircular ports 72, 7'3 therethrough. Nonrotatable plates 53, 57 each have paired ports 75, 75, and 76, 76' therethrough.

Internally toothed outer pump gear 80 is rotatably positioned in opening 79 of gear journalling member 54-, the axis of opening 79 being parallel to and spaced from the axis of crankshaft 4-3. Externally toothed inner pump gear 47 having one less tooth than gear 80 is drivingly positioned on crankshaft extension 46 in mesh with outer gear 80. The eccentric relationship established between the parallel but nonconcentric axes of rotation of pump gears 47, 80 is such that full tooth engagement occurs therebetween at a single point only.

Opening 81 in retainer 44 communicates with a suitable source of fluid to be pumped. Spring 82 between retainer 4 4 and suction port plate 57 resiliently maintains the pump components in operative relationship.

Referring to FIGURE 5, counterclockwise rotation of crankshaft 43 as shown by the arrow drives meshing pump gears 47, in a counterclockwise direction. Stops 61, 62 hold port plates 52, 56, respectively, against counterclockwise rotation. Lubricant is drawn through opening 81 in retainer 44 and suction ports 76, 73 in plates 57, 56 between the teeth of gears 47, 80 and discharged through ports 72, 75 in plates 52, 53 into crankshaft recess 43 and lubricant feed passage 49.

Upon rotation of crankshaft 43, and correspondingly meshing pump gear 47, 80 in the clockwise direction of FIGURE 6, the frictional drag between rotating pump gears 47, 80 and movable discharge and suction port plates 52, 56 moves plates 52, S6 clockwise through an arc of approximately stops 6'1, 62 holding plates 52, 56 against further clockwise movement. Rotation of plate 5 2 interrupts communication between discharge ports 72, 75 and brings port 72 in movable plate 52 opposite port 75 in plate 53. Similarly, rotation of plate 56 interrupts communication between suction ports 73, 76 and brings port 73 in movable plate 56 opposite port 7 6 in plate 57.

Pump gears 47, 80 draw lubricant through retainer opening 8 1 and ports 76', 73 in plates 57, 56 respectively, between the teeth of gears 47, 80, the lubricant discharging through ports 72, 75 in plates 52, 53, respectively, into crankshaft recess 48 and lubricant feed passage 4-9.

By the present invention, applicant has provided an improved gear type pump mechanism automatically reversible upon a reversal in the direction of rotation of the pump driving means; an improved gear type pump mechanism having a simplified construction.

While I have described a preferred embodiment of my invention, it will be understood that my invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

I claim:

1. In an automatically reversible pumping mechanism, the combination of an externally toothed inner pump gear rotatable about a first axis; an internally toothed outer pump gear; a carrier having a gear journalling opening therein dimensioned to rotatably receive said outer gear, the axis of said carrier opening being offset from said first axis, said carrier being adapted to circumscribe said inner gear, said pump gears when rotated forming intake and exhaust spaces; rotatable driving means opera tively secured to said inner gear; means forming suction and discharge passageways including a first port member on one side of said gears having an opening therethrough opposite said intake space and a second port member on the other side of said gears having an opening therethrough opposite said discharge space; and means accommodating predetermined rotation between said carrier and said first and second port members about said first axis upon a reversal in gear rotation to maintain said intake and exhaust spaces opposite said first and second port member openings.

2. A pumping mechanism according to claim 1 in which said carrier is positioned for rotation about said first axis, said rotation limiting means restricting rotation of said carrier to approximately 3. A pumping mechanism according to claim 1 in which said first and second port members are rotatable about said first axis, said rotation limiting means restricting rotation of said first and second port members to approximately 180. 0

4. In an automatically reversible pumping mechanism, the combination of an externally toothed inner pump gear rotatable about a first axis; an internally toothed outer pump gear; a carrier having a gear journalling opening therein dimensioned to rotatably receive said outer gear, the axis of said carrier opening being offset from said first axis, said carrier being adapted to circumscribe said inner gear, said pump gears when rotated forming intake and exhaust spaces; rotatable driving means operatively secured to said inner gear; means forming suction and discha-rge passageways including a first port member on one side of said gears having an opening therethrough opposite said intake space and a second port member on the other side of said gears having an opening therethrough opposite said discharge space; and means accommodating predetermined rota tion between said carrier and said first and second port members about said first axis upon a reversal in gear rotation to maintain said intake and exhaust spaces opposite said first and second port member openings; said suction and discharge passageway forming means including a third port member engaging said first port member having a first opening therein opposite said first port member opening and a fourth port member engaging said second port member having a first opening therein opposite said second port member opening, said third and fourth port members being secured against rotation and having second openings therein substantially opposite said first openings, said first and second port members being rotatable about said first axis upon a reversal in gear rotation to interrupt communication of said first and second port member openings with said third and fourth port member first openings respectively and communicate said first and second port member openings with said third and fourth port member second openings respectively; said rotation limiting means restricting rotation of said first and second port members to approximately 90.

5. In an automatically reversible gear type pumping mechanism, the combination of a member having a gear journalling opening therein mounted for rotation about a first axis, the axis of said member opening being parallel to and offset from said first axis; an externally toothed outer gear disposed in said member opening for rotation about said ofiset axis; an externally toothed inner gear rotatable about said first axis in meshing engagement with said outer gear, said inner and outer gears forming on rotation intake and exhaust spaces; drive means for rotating said inner gear; a first plate-like member on one side of said gears having a port opening therethrough communicable with said exhaust space; a second plate-like member on the opposite side of said gears having an opening therethrough communicable with said intake space; and means accommodating reverse rotation of said journalling member through an arc of substantially 180 on reversal in rotation of said gears to maintain said suction and discharge port plate openings opposite said intake and exhaust spaces.

6. In an automatically reversible gear type pumping mechanism, the combination of an externally toothed inner gear rotatable about a first axis; an internally toothed outer gear; a member having a gear journalling opening therein circumscribing said inner gear, the axis of said member opening being parallel to and offset from said first axis, said outer gear being rotatably positioned in said member gear journalling opening in meshing engagement with said inner gear, said gears when rotated forming intake and exhaust spaces; means for rotating said inner gear; a first plate-like member on one side of said gears rotatable about said first axis and having a port opening therethrough opposite said exhaust space;

a second plate-like member on the other side of said gears rotatable about said first axis and having a port opening therethrough opposite said intake space; and means restraining rotation of said first and second members in the direction of gear rotation, said rotation restraining means permitting reverse rotation of said first and second members through an arc of approximately 180 so that on reversal in the direction of rotation of said gears, said first and second members rotate therewith to maintain said suction and discharge port openings opposite said intake and exhaust spaces.

7. In an automatically reversible gear type pumping mechanism, the combination of an externally toothed inner gear rotatable about a first axis; an internally toothed outer gear; a member having a gear journalling opening therein circumscribing said inner gear, the axis of said member opening being parallel to and offset from said first axis, said outer gear being rotatably positioned in said member gear journalling opening in meshing engagement with said inner gear, said gears when rotated forming intake and exhaust spaces; means for rotating said inner gear; a pair of nonrotatable port members each having first and second spaced openings therethrough; a discharge port member rotatable about said first axis between one of said nonrotatable port members and one side of said gears having an opening therethrough cooperable with said port member first opening to form a discharge passageway; a suction port member rotatable about said first axis between the other of said nonrotatable port members and the opposite side of said gears having an opening therethrough cooperable with said other port member second opening to form a suction passageway; and means restraining said discharge and suction port members against rotation in the direction of gear rotation, said rotation restraining means permitting reverse rotation of said discharge and suction port members through an arc of approximately so that on reverse rotation of said gears said discharge and suction port members rotate therewith to interrupt communication between said discharge port member opening and said first opening and said suction port member opening and said second opening and establish communication between said discharge port member opening and said second opening and said suction port member opening and said first opening.

References Cited by the Examiner UNITED STATES PATENTS Re. 23,086 2/1949 Holl 103-120 2,151,482 3/1939 Neeson 103-126 2,380,783 8/1945 Painter 103-126 2,808,780 10/1957 Hoekstra 103-117 3,120,814 2/1964 Mueller 103-120 3,165,066 1/1965 Phelps et a1 103-126 MARK NEWMAN, Primary Examiner.

SAMUEL LEVINE, Examiner.

W. L. FREEH, Assistant Examiner, 

1. IN AN AUTOMATICALLY REVERSIBLE PUMPING MECHANISM, THE COMBINATION OF AN EXTERNALLY TOOTHED INNER PUMP GEAR ROTATABLE ABOUT A FIRST AXIS; AN INTERNALLY TOOTHED OUTER PUMP GEAR; A CARRIER HAVING A GEAR JOURNALLING OPENING THEREIN DIMENSIONED TO ROTATABLY RECEIVE SAID OUTER GEAR, THE AXIS OF SAID CARRIEER OPENING BEING OFFSET FROM SAID FIRST AXIS, SAID CARRIED BEING ADAPTED TO CIRCUMSCRIBE SAID INNER GEAR, SAID PUMP GEAR WHEN ROTATED FORMING INTAKE AND EXHAUST SPACES; ROTATABLE DRIVING MEANS OPERATIVELY SECURED TO SAID INNER GEAR; MEANS FORMING SUCTION AND DISCHARGE PASSAGEWAYS INCLUDING A FIRST PORT MEMBER ON ONE SIDE OF SAID GEARS HAVING AN OPENING THERETHROUGH OPPSOITE SAID INTAKE SPACE AND A SECOND PORT MEMBER ON THE OTHER SIDE OF SAID GEARS HAVING AN OPENING THERETHROUGH OPPOSITE SAID DISCHARGE SPACE; AND MEANS ACCOMMODATING PREDETERMINED ROTATION BETWEEN SAID CARRIER AND SAID FIRST AND SECOND PORT MEMBERS ABOUT SAID FIRST AXIS UPON A REVERSAL IN GEAR ROTATION TO MAINTAIN SAID INTAKE AND EXHAUST SPACES OPPOSITE SAID FIRST AND SECOND PORT MEMBERS OPENINGS. 